GPS Poor Signal

[giles.holland]

Hi guys, i hope someone can tell me if im doing something wrong?!

Basically i live in the UK, Brighton to be exact. Its not out in the middle of no where or anything so i thought the GPS should be pretty good! at least as good as the TOM TOM is!

but alas, i tested the lap timer going into the centre of town and it thought i was going through building etc, the GPS signal was from RED to YELLOW, (1 bar to 3 bars best) as i say the TOM TOM can do pin point accuracy, so why cant the Harry's Timer?

the software ive got is an Iphone 3GS, so should be able to handle this!

I do alot of Karting and so this would help me alot!

Cheers guys!

Giles

[Harry]

Hi,

First of all, this is not a problem of LapTimer or any software. All apps simply use what they receive from the internal or an external sensor.

On your situation: please check if the TomTom is used at all (e. g. goto the Satellites View). As long as a TomTom is connected, the GPS quality is rated by the number of satellites tracked. Especially in towns with higher buildings, you will have a smaller number of satellites visible. The next point is about accuracy delivered, please check the 'Accuracy' field in the GPS View. It should be below 15m outside of town (and after a reasonable time for stabilizing the receiving conditions).

In case you had the TomTom not connected - the iPhone3Gs has a relatively weak sensor, it improved with the 4th gen a lot.

- Harry

[giles.holland]

hi Harry,

oh so if anything it should be better on a track rather than in the centre of a town?

Im sorry but i didnt explain myself very well, the GPS TOM TOM is a stand alone one i have in the car, and not as an APP on the Iphone.

Ok ive checked my GPS, and its SHOCKING Google map my road, post code is BN1 7BX, is this a built up area?? Ive checked the radius and from the centre of the radius area to the edge is 0.4 miles!!! :O

I havent checked what the GPS is like outside of town or further away from me, is there an official way to check the GPS on a 3GS?

Thanks for your very quick response

[Harry]

O.k., understood. In fact, receiving conditions in towns are worse compared to flat land (or most tracks).

As written above, the 3Gs has not the best GPS receiver, it is clearly inferior to the TomTom stand alone.

Please check you have your iPhone placed in a position with good receiving conditons (in a car directly behind the wind screen).
In case you can not get sufficient accurate, I recommend one of the 5 stars solutions here: http://www.gps-laptimer.de/Compatibility.html

- Harry

[giles.holland]

I'll be using it for Karting in the UK,

Unfortunately i dont think the added hardware will work on a kart as i will need to attach the phone to the steering wheel.

Looks like i'll just have to use other lap timers without GPS and just manually press each lap as i go round i'll give your lap timer a go next time and tell you how it manges it

[Harry]

The XGPS150 is very small and can be tied to your kart easily (there is some hook-and-loop tape included to tie it to your hand wrist).
Especially on kart tracks you need very good GPS to cope with the small distances.

- Harry

[giles.holland]

ok excellent thanks very much for your help!
How much of an increase would this XGPS150 create, i mean for lap times how accurate in timing would it be?

Yes Karting is only done on track lengths from 900metres to 1300metres. so i need a very good GPS.

[Harry]

The XGPS150 - like all solutions allowing direct NMEA access - will have an accuracy of approximately 0.05 seconds in good conditions.

- Harry

[giles.holland]

Harry,

Was about to order the XGPS150 but i cannot receive it as they dont allow shipping to the UK. Is there anywhere else i can get it from or is there anything else similar i can use?

cheers!

[Harry]

I received one directly from the Dual people. They said they are working on a distribution channel for Europe. I'd suggest to contact them.
The alternative without JB is the TomTom.

- Harry